Filter floor



Aug. 19, 1930.;

D. 0. WHIIITACRE FILTER FLOOR Filed Oct. 29, 1927 2 SheetsShee 1' Egg D. D. WHITACRE Aug. 19, 1930.

FILTER FLOOR 1 Filed Oct. 29, '1'92'? /0 2 Sheets-Sheet 2 Patented Aug. 19, 1936 LTZSAI? .noimnn 1). wr rraonn, or menswear OHIO FILTER FLOOR "Application filed October 29, 192. Serial No. 229,732.

. This invention relates to false fioor construction or aeration tile for trickle filters -used1n sewage treatment. I 7

Trickle filters are commonly constructed to comprise a bedof aggregate, whichmay in a given instance be crushed stoneof about .2 inch mesh, through which sewage is allowed to fiow'and in which bacterial activity causes purification or 'stablization of effluent. 1c The bed of aggregate or like material is supported on" a false flooring through which the effluent is drained and carried away from the filter. Intrickle'filters it has been found desirable to make the drains or falsefloor of clay products, in some instances-glazedor vitrified, sothatf. the drains will not become clogged by various growths or solid matter suspended in the sewage. In the spring of the year the bed of the filter tendsto clean ZG itself and discharge a relatively higlr quantity of suspended matter which tends to clog the drains. Ifind it desirable tomake the drain openings largeenough so that they may. bereadily cleaned, if. necessary, but I 35 find it, of'great advantage to .constructthe drains with a cross section which will tend to accelerate the flow in the bottom portion .of the drain so that it will be self, cleaning. It is among the objeetsof my invention to construct a falsefioor of channel tile comprising the drains proper an'dtil'e grids spanning the channels and supporting theaggregate or filter bed. A. further object is to extrude and cut the channel tileto reduce the tendency to warp when burning. Another object'is to provide separate load carrying portions on the bottom of the channel tile so that the load may be carried directly by .1 the vertical walls of the tile. A further ob- 40 ject is to'arrange and construct thegri ds so that a maximum ratio of passageway or void is provided consistent with necessary strength and minimum thickness. A. further object is to conform the size of the grids tothe size of the channel tile so that one channel a Y tile and a given number of grids form a com 'plete and independent load carrying unit.

' Anotherobject is to provide a seat or bed for i the grids on theload bearing portions of the supporting tile.'

facilitate draining.

' Other objects of my invention will appear from the following description reference being had to :the accompanying drawings wherein a preferred form thereof is illustrated. The essential characteristics are summarized in the claims.

Fig. l is a fragmentary perspective showing the false fioor structure and the filter bed;

Fig. 2 is an endelevation of the false floor; Fig. 8 is a partial plan of the floor showing the grid superimposed'on the channel'tile; Fig. 4 shows the manner of extruding the channel tile; and Fig. 5 is a modifiedform of the channel tile. l

. Incarryingout the objects of myinvention and referring particularly to Fig. l, I show a concretefioor 1 on which-the false flooring is laid." In laying the false floor, it may be found desirable-to spread a thin layer of rout or mortar 2 on which thechannel tile 3 are set. The channel tile maybe laid iii-parallel rowsextending across the bottom .of the filter,'the filter bottom being slightly inclined in the direction of thechannels to The tile 3 may be displaced longitudinally relative to each other, if desired, and are laid side by sidewand end to end to completely cover the floor 1. f

(Referring also to Fig. 2, Ishow a channel tilehaving sidewalls 4L and a bottom shell 5 and inwardly inclined webs 6, which 'define the contour of the efiiuent stream. Suitable voids '7 facilitate burning. The webs and shells may be of less thickness than the load bearing walls 4. As pointed out above,

I have found it advantageous-to causev the efliuent to flow rapidly particularly in the bottom of the channel to carry away sedimentor other obstructing matter. With this thought in/mind, I causethe surfaces of the *websfi to defineinclined planes as shown in Fig. 2.. Tn Fig. 5, the walls are formed with convex surfaces toward the stream as at: 6. It will be seen in the. first instancethat the cross sectional area of the stream. decreases at least as rapidly asthe depth of the stream,

while in the second instance the cross sec tional area of the stream decreases more rapidly than the depth of the stream. chan- Referring particularly to Fig. 5, I show ,a preferred manner of extruding the channel tile, that is, the tiles are extruded in pairs, as at 3 and 3 and are dried and burned while joined together, as shown. In the extruding transverse cuts .orcurfs are made as shown at so that the pairs may be separated after they are burned. hen the pairs are separated, they are fractured along the lines F, leaving a portion of the top surface of the walls more or less rough. By this procedure I form the tops of the walls 4 with a depressed smooth surface along the curf as at 9 and a relatively raised rough surface along the plane of fracture as at 10. The raised roughened surface 10 serves as a guide or flange for positioning and holding the grids against lateral displacement.

As mentioned above, I employ tile grids which span the channels and I provide a certain number of grids (two are illustrated) for each channel tile. The lateral dimension of the grid may be a little less than the lateral dimension of the channel tile, so that'the grid may be seated and accurately positioned on the upper surfaces -9 of the -walls 4 and within the fractured surfaces 10.

In this manner the grids of laterally adjacent units are spaced apart as at 11, thereby providing a passageway for the effluent between the ends of adjacent grids. The grids may all be of similar size and may be formed to have end walls 21 and side walls 22 (see Fig. with suitable voids 23 through which effluent may descend into the channels. I have found it desirable for 'grids of given depth that the cross section of all the webs and shells of the grids in a given area constitute about of that area. The grid blocks may preferably have spacing abutments 24 on the sidewalls (see also Fig. 1),

for spacing the blocks apart longitudinally of he drains and for providing openings 25 into the drains from the spaces ll'between {laterally adjacent grids.

Referring particularly to Fig. I show that the side walls 4 of thebhann'el tile depend slightly below the bottom surface of the bottom shell-5, and constitute longitudina'lly extending bearing portions or feet 8. The hearing portionss may am flat bottom surfaces between the points and it is advantageousto "have these points vertical alignment with the edgesof the upper -load bearing surface -9,"designate,d FF. Inother words, the points E are in vertical alignment with the points It will appear from the foregoing that a false floor constructed according to my invention comprises a number of independent and self-sustaining units, each of which carries its proportional share of the load of the filter bed. It will further appear that the grids and channel tile are designed to fit together in permanent relative positions and that the load from the grids is carried directly and vertically onto the foundation of the bed; that an economy of grid material is effected by spacing the several grids apart and that the spacings between the grids are effectively used as passageways for efiiuent. It will further appear that the lateral spacing of the grids is effected by causing the tops of the side walls of the channels to have accurately defined seatingsurfaces and that such surfaces are arranged in vertical alignment with the bottom load bearing portions of the walls. Channel tile constructed according to my invention provide maximum strength and minimum weight inasmuch as all of the external load is taken through vertical walls so that the remaining webs and shells may be proportionately lighter. Itwill further appear that drains constructed according to my invention tend to be self-cleaning thereby reducing the operating cost and adding to the efficiency of the filter.

While I have illustrated and described a preferred form of my invention, I do not care to be limited in the scope thereof other than by the claims appended hereto.

I claim:

1. A false floor for trick filters including open drain tile adapted to support laterally extending grid blocks, said drain tile having inclined converging inner walls, a bottom wall and load carrying side walls, joined to said-first-named walls, the inner top surfaces of the side walls defining smooth load hearing seats for said grid blocks and the bottoms of side walls forming load carrying extensions vertically aligned with said seats and depending below the bottom wall and holding the bottom wall elevated.

2. In a false floor for trickle filters positioned on a permanent flooring and adapted to carry afiltei' bed, the combination of drain :tile forming openehann'e'ls and having jload .car rying side'walls, saidldrain tile bei g laid side by side andzend to end to form parallel channels unde-r said bed, the top surfaces of said side walls comp-rising innerand outer portion, the inner Po tion being-smooth and depressed relative to the outer portion; grid blocks spanning the channels and having their ends seated on said smooth inner pertions, the ends of laterally adjacent grid blocks being spaced-apart above said raised eater portions of the side walls, the-lead carrying side walls extending below the body of the blocks and forming load cerryingieet a vertically aligned with the supported ends of said grid blocks. i I 3. A false floor for trickle filter comprising open drain tile having load bearing side Walls, grid blocks spanning the drains and carried by said side Walls, the top surfaces of said side walls having relatively depressed seat portions for the ends of said grid blocks, the bottoms of said side walls extending be- 10 low the body of said tile and having a load bearing surface, the longitudinal edges of whichare in substantial vertical alignment t with the longitudinal edges of the said sea-t portions on the top of the wall andthe sup- 15 ported ends of the grid blocks.

4. A false floor for trickle filter formed of separate units, each unit comprising open 7 drain tile having load bearing side Walls, and grid blocks spanning the drain and carried 30 by, said side walls, the top surfaces of said. side Walls having relatively depressed seat portions for the ends of said grid blocks, the bottoms of vsaid side Walls extending below the body of said tile and having a load bearing surface, the longitudinal edges of which are in vertical alignment with the longitudinal edges of the said seat portions for said grid blocks, each of said drain tile carrying a multiple of whole grid blocks'and forming an :10 independent load carrying unit, and projections on the sides of said grid blocks spaced inwardly from the inner edges of the side walls of the drain tile for spacing the grid blocks apart longitudinally.

as In testimony whereof, I hereunto aflix my signature.

DONALD D. WHITACRE. 

